Fix devstack option to plugin zaqar
Fix devstack option to plugin zaqar

As per zaqar development-environment.rst,
To integrate zaqar in an openstack environment,
we need to enable zagar service by adding the below line to the devstack local.conf
	enable_service zaqar-server
However, now zaqar add as a plugin (not as a devstack service) to
the devstack environment by adding below line to the devstack local.conf
	enable_plugin zaqar https://github.com/openstack/zaqar
This patch is fixed the issue.
Closes-Bug: #1496233

Change-Id: I677257c2f3ae4caa3f39fde2fabee9ee5c113a5c

openstack/zaqar,openstack/zaqar,openstack/zaqar,openstack/zaqar